Field of the Invention and Related Art Statement
The present invention generally relates to an optical card technique, and more particularly to a method and an apparatus for manufacturing an optical card.
In a known method of manufacturing an optical card of ROM type, a sheet 1 is unwound from a sheet roll as illustrated in FIG. 1, and then is exposed via a plurality of masks 2 each corresponding to respective optical cards as shown in FIG. 2. As depicted in FIG. 3A, the sheet 1 is composed of a lamination of a transparent protection substrate 3, a metal reflection layer 4 such an aluminum layer and a photosensitive layer 5. The photosensitive layer 5 is exposed in accordance with a pattern corresponding to the information to be recorded and born on the mask 2. Then, the photosensitive layer is developed to remove exposed portions thereof as shown in FIG. 3B. Next, the metal reflection layer 4 is selectively etched while the developed photosensitive layer 5 is used as a mask for the etching. After that, the photosensitive layer 5 is removed as illustrated in FIG. 3C. Then, a card substrate 7 having an opaque layer 6 applied on its surface is adhered onto the metal reflection layer 4 as depicted in FIG. 3D. Finally, the sheet 1 is cut into respective optical cards.
In the known method explained above, the information is recorded on the optical card with the aid of the mask 2. It requires a relatively long time for manufacturing and checking the mask. Further, when a relatively smaller number of optical cards are formed from the single mask, the cost for manufacturing the mask per a single optical card would be also increased, so that the cost of the optical card would be also increased.